Blade-mounting means.



UNITED STATES PATENT OFFICE.

CHARLES E. SWEET, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO THE WEST-INGHOUSE MACHINE COMPANY, A CORPORATION OF PENNSYLVANIA.

BLADE-MOUNTING MEANS.

Specification of Letters Patent.

Patented Jan. 4, 1910.

Application filed July 30, 1908. Serial No. 446,099.

To all whom it may concern:

Be it known that I, CHARLES E. SWEET, a citizen of the United States,and a resident of Wilkinsburg, in the county of Allegheny and State ofPennsylvania, have made a new and useful Invention in Blade-MountingMeans, of which the following is a specification.

This invention relates to elastic fluid turbines and more particularlyto blading means for such turbines.

An object of this invention is the production of means for assemblingthe blades into rings or ring segments before they are secured to theblade-carrying element of the turbine.

In carrying out my invention I provide a binding member for the bladesand the intermediate spacing pieces, which are located between theblades. The base of each blade is provided with a slot which is adaptedto register with a similarly shaped slot provided in each intermediatespacing piece. These slots in the blades and spacing pieces cooperate inreceiving and holding in place the binding member, which secures theblades and spacing pieces into a blade ring or ring segment.

In the drawings accompanying this application and forming a partthereof: Figure 1 is a transverse fragmental section of the rotorelement of a turbine provided with blades (shown in elevation) mountedin accordance with my invention; Fig. 2 is a partial plan view of arotor element provided with blades; Fig. 3 is a fragmental longitudinalsection of a turbine and discloses fragmental sections of the rotor andstator of a turbine, respectively provided with blades and vanes mountedin accordance with my invention; Fig. 4 is an elevation of a bladeforming a detail of my invention; and Fig. 5 is a perspective view of aspacing piece embodied in my invention.

Throughout the specification and in the claims I will utilize the termsblade and blades in their broadest sense, that is to mean either therotating blades or the stationary vanes of the turbine, and the termblade-carrying element will be employed to denote either the stationaryor rotating blade-carrying elements'of the turbine.

Turbine blade carrying elements 6 are each provided with a plurality ofundercut blademounting slots 7 in which blade rings, which comprisealternately arranged blades 8 and spacing pieces 9, are secured by meansof compound tapered wedges 10. Protective strips 11 are located on theblade-carrying element between each blade-mounting slot. One flange ofeach strip extends into an adjacent slot and, with the blade ring, issecured in place by the compound tapered wedges 10.

Each blade 8 is substantially crescent shaped in cross-sectionthroughout its length. The intermediate spacing pieces are adapted tofit'snugly between the mounting ends of the blades when the blades andpieces are as sembled in segmental rings. Each intermediate spacingpiece is provided with curved end faces, one of which is convex andcorre sponds in contour to the concave faces of the blades, and theother is concave and corresponds in contour to the convex faces of theblades. These faces are inclined to each other so that, when the bladesand pieces are assembled in a ring, the blades will extend radially. Onelateral face of each piece is inclined to correspond to the inclinationof the undercut walls of the slots. The other lateral face extends atright angles or is normal to the top and top faces of the pieces whichare parallel to each other.

A slot 12 is cut across one end of each blade and a slot 13 is cutacross the bottom face of each spacing piece. The slots 12 and 13 areadapted to register with each other when the blades and pieces areassembled, and they cooperate in receiving a binding member 1 1-. whichextends longitudinally of the assembled blades and pieces.

Each slot 12 and 13 is enlarged at its inner end to an aperture ofcircular cross section. The binding member 14 is formed, from a flatstrip, into an arch-shaped member of T-section and is provided with aflange 15 of circular cross section which is adapted to fit into theenlarged portion of each of the slots 12 and 13. The other flange of themember is fiat and is adapted to lie in close proximity with the basesof the blades and the intermediate pieces on each side of theirrespective slots. The web portion of the T- shaped section fits snuglyinto the narrower portion of each slot.

Blades and alternate spacing pieces are strung onto the binder memberand, if desired, are locked in place by being secured, in any suitablemanner, against longitudinal motion. The spacing pieces and the bindingmember form a base strip for the blades which is adapted to be securedinto one of the blademounting slots 7 The outer or free ends of theblades are provided with comma-shaped apertures 16 through which abinding wire 17 of commashaped cross section extends. The binding wireis secured to the blades by having the tail shaped fin 18, with which itis provided, sheared and bent over between adjacent blades. The bentover portions form spacers which look the outer ends of the bladesagainst relative motion.

After the blades and spacing pieces are assembled into segmental rings,they are secured into the mounting slot 7 by means of the wedges 10.Each segmental ring is so located within the slot that the inclinedfaces of the spacing pieces 9, comprised in the ring, contact with oneof the undercut walls of the slot. Each protective strip 11 is providedwith a flange 19 which is adapted to project into a slot 7 when thestrip is in place between the slots, 011 the blade-carrying element.

The wedges 10 are introduced into the slot in pairs and are locatedbetween the normal faces of the pieces 13 comprised in the blade ringand the flange of the protective strip. The wedges are so constructedand are so arranged that, when driven home, the two wedges of each pairconjointly form a wed e-shaped key which effectively secures the bladering and the flange 19 of the protective strip in place, and which isprevented, by its shape and the shape of its component wedges, frombeing dislodged from the slot by centrifugal or any other force.

Lugs or flanges 20 are formed integrally with each piece 9 and arelocated near the top of the piece and on the same side as the inclined.face. These flanges project from the slot 7 when the blade rings are inplace and are adapted to overhang and engage the outer or free edge ofthe protective strip 111., which is secured into the next adjacent s 0t7.

A number of wedges are employed to secure each segmental ring into aslot 7 and they are preferably so spaced that the com ponent wedges ofone pair abut against the component wedges of the next adjacent pairs.Since it is necessary to leave considerable space between the first andlast pairs of wedges introduced into a slot, some special means must beemployed for se curing the component wedges of these pairs againstlongitudinal movement.

In accordance with the provisions of the patent statutes I havedescribed an apparatus which I now consider to represent the bestembodiment of my invention, but I desire to have it understood that theapparatus shown is only illustrative and that the invention can becarried out by other means.

What I claim is: p

1. In combination with a blade-carrying element provided with a slot,blades, a plu rality of intermediate spacing pieces, a combined base andbinding member for said blades and pieces, and means for securing saidblades and pieces in said slot.

2. In combination with a blade-carrying element provided with ablade-mounting slot, a plurality of alternately arranged blades andspacing pieces, a binding member therefor located in holes provided inthe ends of the blades and the bottom faces of the bases, and means forsecuring said blades and pieces into said slot.

3. In combination with a turbine bladecarrying element provided withalternately arranged blades and spacing pieces, a base strip contactingwith the ends of the blades and the bottom faces of the bases and provided with a flange, which projects into notches provided in said bladesand said pieces, and means for securing said blades and pieces to saidelement.

4. A segmental blade ring comprising alternately arranged blades andspacing pieces, and a base piece provided with a flange which projectsinto slots provided in the bases of the blades and the bottom faces ofthe pieces.

5. A segmental blade ring comprising alternately arranged blades andintermediate spacing pieces, and a combined base strip and bindingmember for the blades and pieces.

6. A segmental blade ring comprising alternately arranged blades andspacing pieces, and a base piece provided with means for binding saidblades and pieces together.

7. A segmental blade ring comprising alternately arranged blades andspacing pieces, and a T-shaped binding member for said blades andpieces.

In testimony whereof, I have hereunto subscribed my name this 23rd dayof July, 1908.

CHARLES E. SIVEET.

Vitnesses C. W. MCGHEE, E. IV. MoCALmsTnn.

